1 files changed, 111 insertions, 0 deletions
diff --git a/xsft.py b/xsft.py
new file mode 100755
index 0000000..3846b85
--- /dev/null
+++ b/xsft.py
@@ -0,0 +1,111 @@
+#!/usr/bin/python3
+
+import math
+import subprocess
+
+from gi.repository import Gtk
+
+
+def xrandr(args):
+    cmd = ['xrandr'] + args
+    return subprocess.check_output(cmd).decode('utf-8')
+
+
+def get_connected_outputs():
+    for line in xrandr([]).splitlines():
+        if line.startswith(' '):
+            continue
+        words = line.split()
+        if words[1] == 'connected':
+            yield words[0]
+
+
+def set_brightness_and_gamma(outputs, brightness, gamma):
+    args = []
+    for output in outputs:
+        args += ['--output', output,
+                 '--brightness', str(brightness),
+                 '--gamma', '{}:{}:{}'.format(gamma[0], gamma[1], gamma[2])]
+    print(' '.join(args))
+    xrandr(args)
+
+
+def color_temperature_to_rgb(kelvin):
+    """Adapted from tannerhelland.com/4435."""
+    temp = kelvin / 100.0;
+
+    if temp <= 66:
+        red = 255
+
+        green = temp
+        green = 99.4708025861 * math.log(green) - 161.1195681661
+
+        if temp <= 19:
+            blue = 0
+        else:
+            blue = temp-10
+            blue = 138.5177312231 * math.log(blue) - 305.0447927307
+    else:
+        red = temp - 60
+        red = 329.698727446 * math.pow(red, -0.1332047592)
+
+        green = temp - 60
+        green = 288.1221695283 * math.pow(green, -0.0755148492 )
+
+        blue = 255
+
+    def clamp(val):
+        if val < 0:
+            return 0
+        elif val > 255:
+            return 255
+        else:
+            return val
+
+    return [clamp(red), clamp(green), clamp(blue)]
+
+
+def temperature_to_gamma(kelvin):
+    rgb = color_temperature_to_rgb(kelvin)
+    fac = sum(rgb) / 3
+
+    for i in range(3):
+        rgb[i] /= (fac)
+
+    return rgb
+
+
+class MyWindow(Gtk.Window):
+    def __init__(self):
+        Gtk.Window.__init__(self, title="xrandr-slightly-fewer-tears")
+        self.set_default_size(640, -1)
+
+        self.box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, border_width=10)
+        self.add(self.box)
+
+        self.box.add(Gtk.Label('Brightness'))
+        self.brightness = self.add_hscale(20, 100)
+        self.box.add(Gtk.Label('Temperature (K)'))
+        self.temperature = self.add_hscale(1000, 40000)
+
+    def add_hscale(self, min_val, max_val):
+        scale = Gtk.Scale(orientation=Gtk.Orientation.HORIZONTAL, digits=0)
+        scale.set_range(min_val, max_val)
+        scale.connect('value-changed', lambda _: self.update())
+        self.box.add(scale)
+        return scale
+
+    def update(self):
+        brightness = self.brightness.get_value() / 100.0
+        if brightness < 0.2:
+            brightness = 0.2
+
+        set_brightness_and_gamma(get_connected_outputs(),
+                                 brightness,
+                                 temperature_to_gamma(self.temperature.get_value()))
+
+
+win = MyWindow()
+win.connect("delete-event", Gtk.main_quit)
+win.show_all()
+Gtk.main()